The red PCB seen at the center of the rats-nest is a Papilio FPGA board. They still want to use it to drive the installation, but a new hardware interface is necessary. The solution is to design what they call a megawing (wings are to Papilio as shields are to Arduino). The LEDs will be in RGB strip form, so one of the requirements is to supply enough connectors to drive 16 channels of SPI devices. The wing will also include the 48V power source and connectors for the condenser microphone that serves as an input for the SoundPuddle. There are also two other options for audio input, one via a Bluetooth module (which can double as a control device) and the other via MIDI.

After the break you can see a lighting demo. Be ready with the volume controls as most of the sounds used in the test are quite annoying.

They used a PC running processing and 5 low-cost USB to 8 SPI output boards, driving a total of 40 LED strips.

Here’s the code I wrote which was the starting point for the PC-to-6400-LED interface. It shows up as a normal serial port, so it’s easy to interface with Processing or other software. No special drivers needed.

It must be quite a problem powering and controlling a lot of LED since we are still waiting for those full-size OLED screens, showing that the big japanese and korean companies can’t easily do it either.

That’s what’s holding up OLED displays in large sizes, laying down 6,220,800 LED elements without a flaw.

It took a while for color LCD technology to get to the point where failed panels were very rare, ‘course LCD developed in stages from monochrome to passive scan to dual scan to active matrix and all through many steps in increasing resolution.

For OLED the consumer wants those 6.2 million little colored light emitters right now. The LED screens on some phones are serving the place that smaller laptop screens did for LCD.

Plasma screens have used a fairly simple method of defect management. Use more than one little electron gun per color element. It’s as easy to do that as it is to make one per, and if a few happen to not work those elements will just be slightly dimmer, or it could be possible to program the controller to drive them a tiny bit hotter. If some fail in use the panel doesn’t get a dead element, which would cause the 3-color pixel to always be off in color.

check out the maxim site as they have driver chips specifically designed for large led displays, complete with rgb support if needed. The chips are about $6 each but a single chip can control 128 different LED.http://www.maxim-ic.com/datasheet/index.mvp/id/4910

The maxim chips if interconnected can do an RGB display of 32,000 pixels, that is 3 led for each pixel with brightness controls. You will need to use a 4 wire spi 10Mb/sec interface for something that large, refresh rate could display 50fps video.